/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.internal.widget.multiwaveview;
import java.util.ArrayList;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.drawable.Drawable;
import android.util.FloatMath;
import android.util.Log;
public class PointCloud {
private static final float MIN_POINT_SIZE = 2.0f;
private static final float MAX_POINT_SIZE = 4.0f;
private static final int INNER_POINTS = 8;
private static final String TAG = "PointCloud";
private ArrayList<Point> mPointCloud = new ArrayList<Point>();
private Drawable mDrawable;
private float mCenterX;
private float mCenterY;
private Paint mPaint;
private float mScale = 1.0f;
private static final float PI = (float) Math.PI;
// These allow us to have multiple concurrent animations.
WaveManager waveManager = new WaveManager();
GlowManager glowManager = new GlowManager();
private float mOuterRadius;
public class WaveManager {
private float radius = 50;
private float alpha = 0.0f;
public void setRadius(float r) {
radius = r;
}
public float getRadius() {
return radius;
}
public void setAlpha(float a) {
alpha = a;
}
public float getAlpha() {
return alpha;
}
};
public class GlowManager {
private float x;
private float y;
private float radius = 0.0f;
private float alpha = 0.0f;
public void setX(float x1) {
x = x1;
}
public float getX() {
return x;
}
public void setY(float y1) {
y = y1;
}
public float getY() {
return y;
}
public void setAlpha(float a) {
alpha = a;
}
public float getAlpha() {
return alpha;
}
public void setRadius(float r) {
radius = r;
}
public float getRadius() {
return radius;
}
}
class Point {
float x;
float y;
float radius;
public Point(float x2, float y2, float r) {
x = (float) x2;
y = (float) y2;
radius = r;
}
}
public PointCloud(Drawable drawable) {
mPaint = new Paint();
mPaint.setFilterBitmap(true);
mPaint.setColor(Color.rgb(255, 255, 255)); // TODO: make configurable
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mDrawable = drawable;
if (mDrawable != null) {
drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
}
}
public void setCenter(float x, float y) {
mCenterX = x;
mCenterY = y;
}
public void makePointCloud(float innerRadius, float outerRadius) {
if (innerRadius == 0) {
Log.w(TAG, "Must specify an inner radius");
return;
}
mOuterRadius = outerRadius;
mPointCloud.clear();
final float pointAreaRadius = (outerRadius - innerRadius);
final float ds = (2.0f * PI * innerRadius / INNER_POINTS);
final int bands = (int) Math.round(pointAreaRadius / ds);
final float dr = pointAreaRadius / bands;
float r = innerRadius;
for (int b = 0; b <= bands; b++, r += dr) {
float circumference = 2.0f * PI * r;
final int pointsInBand = (int) (circumference / ds);
float eta = PI/2.0f;
float dEta = 2.0f * PI / pointsInBand;
for (int i = 0; i < pointsInBand; i++) {
float x = r * FloatMath.cos(eta);
float y = r * FloatMath.sin(eta);
eta += dEta;
mPointCloud.add(new Point(x, y, r));
}
}
}
public void setScale(float scale) {
mScale = scale;
}
public float getScale() {
return mScale;
}
private static float hypot(float x, float y) {
return FloatMath.sqrt(x*x + y*y);
}
private static float max(float a, float b) {
return a > b ? a : b;
}
public int getAlphaForPoint(Point point) {
// Contribution from positional glow
float glowDistance = hypot(glowManager.x - point.x, glowManager.y - point.y);
float glowAlpha = 0.0f;
if (glowDistance < glowManager.radius) {
float cosf = FloatMath.cos(PI * 0.25f * glowDistance / glowManager.radius);
glowAlpha = glowManager.alpha * max(0.0f, (float) Math.pow(cosf, 10.0f));
}
// Compute contribution from Wave
float radius = hypot(point.x, point.y);
float waveAlpha = 0.0f;
if (radius < waveManager.radius * 2) {
float distanceToWaveRing = (radius - waveManager.radius);
float cosf = FloatMath.cos(PI * 0.5f * distanceToWaveRing / waveManager.radius);
waveAlpha = waveManager.alpha * max(0.0f, (float) Math.pow(cosf, 6.0f));
}
return (int) (max(glowAlpha, waveAlpha) * 255);
}
private float interp(float min, float max, float f) {
return min + (max - min) * f;
}
public void draw(Canvas canvas) {
ArrayList<Point> points = mPointCloud;
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.scale(mScale, mScale, mCenterX, mCenterY);
for (int i = 0; i < points.size(); i++) {
Point point = points.get(i);
final float pointSize = interp(MAX_POINT_SIZE, MIN_POINT_SIZE,
point.radius / mOuterRadius);
final float px = point.x + mCenterX;
final float py = point.y + mCenterY;
int alpha = getAlphaForPoint(point);
if (alpha == 0) continue;
if (mDrawable != null) {
canvas.save(Canvas.MATRIX_SAVE_FLAG);
final float cx = mDrawable.getIntrinsicWidth() * 0.5f;
final float cy = mDrawable.getIntrinsicHeight() * 0.5f;
final float s = pointSize / MAX_POINT_SIZE;
canvas.scale(s, s, px, py);
canvas.translate(px - cx, py - cy);
mDrawable.setAlpha(alpha);
mDrawable.draw(canvas);
canvas.restore();
} else {
mPaint.setAlpha(alpha);
canvas.drawCircle(px, py, pointSize, mPaint);
}
}
canvas.restore();
}
}
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